YSK: In the US, hospitals are required to help pay for your medical bills if you make under a certain amount of money (typically 200-300% of the Federal Poverty Level). This could potentially cover the entirety of your hospital bill.
from /r/YouShouldKnow
YSK：在美国，如果你的收入低于一定数额（通常是联邦贫困线的200-300%），医院必须帮助支付你的医疗费用。这有可能涵盖你的全部医院账单。